[Ocfs2-devel] [PATCH 1/5] ocfs2: Provisions for sysfs entries

Gang He ghe at suse.com
Tue May 31 19:34:37 PDT 2016




>>> 

> 
> On 05/30/2016 02:53 AM, Gang He wrote:
>> Hello Goldwyn,
>>
>> Thanks for your code, my comments are inline.
>>
>>
>>>>>
>>> From: Goldwyn Rodrigues <rgoldwyn at suse.com>
>>>
>>> This adds /sys/fs/ocfs2/<s_id> to the sys filesystem. This
>> Gang: My suggestion is to create a sysfs directory device_name under 
> /sys/fs/ocfs2 per each file system,
>> The file system generic attributes should be located under this top sub 
> directory /sys/fs/ocfs2/<s_id>,
>> but we should create a separate sub directory (e.g. filecheck) under this 
> top sub directory for file check feature,
>> then, all the file check related attributes should be located under that 
> directory /sys/fs/ocfs2/<s_id>/filecheck.
>> You know, in the future, we maybe add more attributes/sub directories under  
> /sys/fs/ocfs2/<s_id>,
>> I should make sure the file check feature is not mixed with other things, it 
> is easy to read/debug for the users/developers.
>>
> 
> I don't think keeping it separate is important. We would need a separate 
> kset for incorporating all of this. Besides, mulitple redirections will 
> mess it up more than keep it simple. However, we should document what 
> each portion is used for.
> 
> I don't see a point in using multiple structures when they would not be 
> references at multiple points, at least in this case.
Gang: I prefer to use a separate sysfs directory for file check things, you know, maybe in the future
there will be more and more generic attributes under <device_name> sysfs directory for each file system.
this will make the thing complicated, but actually the existing code have done like that, just re-use the code.
But anyway, it is not too important for using/not using a separate sysfs directory for file check, I just worry about the future.  

>  
> 
>>> is done by adding the kobj into the ocfs2_super. All other
>>> files are added in this directory.
>>>
>>> Introduce ocfs2_sb_attr which encompasses the store() and show() functions.
>>> Move all the important data structures with respect to filechecks
>>> to ocfs2_super.
>>>
>>> More superblock information should move in here.
>>>
>>> Signed-off-by: Goldwyn Rodrigues <rgoldwyn at suse.com>
>>> ---
>>>   fs/ocfs2/Makefile |  3 +-
>>>   fs/ocfs2/ocfs2.h  |  4 +++
>>>   fs/ocfs2/super.c  |  7 +++--
>>>   fs/ocfs2/sysfs.c  | 92
>>> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>   fs/ocfs2/sysfs.h  |  9 ++++++
>>>   5 files changed, 111 insertions(+), 4 deletions(-)
>>>   create mode 100644 fs/ocfs2/sysfs.c
>>>   create mode 100644 fs/ocfs2/sysfs.h
>>>
>>> diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile
>>> index e27e652..716ed45 100644
>>> --- a/fs/ocfs2/Makefile
>>> +++ b/fs/ocfs2/Makefile
>>> @@ -41,7 +41,8 @@ ocfs2-objs := \
>>>   	quota_local.o		\
>>>   	quota_global.o		\
>>>   	xattr.o			\
>>> -	acl.o	\
>>> +	acl.o			\
>>> +	sysfs.o			\
>>>   	filecheck.o
>>>
>>>   ocfs2_stackglue-objs := stackglue.o
>>> diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
>>> index e63af7d..8e66cdf 100644
>>> --- a/fs/ocfs2/ocfs2.h
>>> +++ b/fs/ocfs2/ocfs2.h
>>> @@ -37,6 +37,7 @@
>>>   #include <linux/mutex.h>
>>>   #include <linux/lockdep.h>
>>>   #include <linux/jbd2.h>
>>> +#include <linux/kobject.h>
>>>
>>>   /* For union ocfs2_dlm_lksb */
>>>   #include "stackglue.h"
>>> @@ -472,6 +473,9 @@ struct ocfs2_super
>>>   	 * workqueue and schedule on our own.
>>>   	 */
>>>   	struct workqueue_struct *ocfs2_wq;
>>> +
>>> +	struct kobject kobj;
>>> +	struct completion kobj_unregister;
>>>   };
>>>
>>>   #define OCFS2_SB(sb)	    ((struct ocfs2_super *)(sb)->s_fs_info)
>>> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
>>> index d7cae33..96b7a9f 100644
>>> --- a/fs/ocfs2/super.c
>>> +++ b/fs/ocfs2/super.c
>>> @@ -75,6 +75,7 @@
>>>
>>>   #include "buffer_head_io.h"
>>>   #include "filecheck.h"
>>> +#include "sysfs.h"
>>>
>>>   static struct kmem_cache *ocfs2_inode_cachep;
>>>   struct kmem_cache *ocfs2_dquot_cachep;
>>> @@ -1200,8 +1201,8 @@ static int ocfs2_fill_super(struct super_block *sb,
>>> void *data, int silent)
>>>   	/* Start this when the mount is almost sure of being successful */
>>>   	ocfs2_orphan_scan_start(osb);
>>>
>>> -	/* Create filecheck sysfile /sys/fs/ocfs2/<devname>/filecheck */
>>> -	ocfs2_filecheck_create_sysfs(sb);
>>> +	/* Create sysfs entries */
>>> +	ocfs2_sysfs_sb_init(sb);
>>>
>>>   	return status;
>>>
>>> @@ -1651,9 +1652,9 @@ static void ocfs2_put_super(struct super_block *sb)
>>>   {
>>>   	trace_ocfs2_put_super(sb);
>>>
>>> +	ocfs2_sysfs_sb_exit(sb);
>>>   	ocfs2_sync_blockdev(sb);
>>>   	ocfs2_dismount_volume(sb, 0);
>>> -	ocfs2_filecheck_remove_sysfs(sb);
>>>   }
>>>
>>>   static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
>>> diff --git a/fs/ocfs2/sysfs.c b/fs/ocfs2/sysfs.c
>>> new file mode 100644
>>> index 0000000..e21e699
>>> --- /dev/null
>>> +++ b/fs/ocfs2/sysfs.c
>> Gang: please add source file comments like other source files.
>>
>>> @@ -0,0 +1,92 @@
>>> +#include "ocfs2.h"
>>> +#include "sysfs.h"
>>> +
>>> +struct ocfs2_sb_attr {
>>> +	struct attribute attr;
>>> +	ssize_t (*show)(struct ocfs2_super *, struct ocfs2_sb_attr *,
>>> +			char *buf);
>>> +	ssize_t (*store)(struct ocfs2_super *, struct ocfs2_sb_attr *,
>>> +			const char *buf, size_t count);
>>> +};
>>> +
>>> +#define OCFS2_SB_ATTR(_name, _mode) \
>>> +struct ocfs2_sb_attr sb_attr_##_name = __ATTR(name, _mode, _show, _store)
>>> +
>>> +#define OCFS2_SB_ATTR_RO(_name) \
>>> +struct ocfs2_sb_attr sb_attr_##_name = __ATTR_RO(_name)
>>> +
>>> +static ssize_t ocfs2_sb_attr_show(struct kobject *kobj,
>>> +		struct attribute *attr, char *buf)
>>> +{
>>> +	struct ocfs2_sb_attr *oa =
>>> +		container_of(attr, struct ocfs2_sb_attr, attr);
>>> +	struct ocfs2_super *osb = container_of(kobj, struct ocfs2_super, kobj);
>>> +	if (!oa->show)
>>> +		return -EIO;
>>> +
>>> +	return oa->show(osb, oa, buf);
>>> +}
>>> +
>>> +static ssize_t ocfs2_sb_attr_store(struct kobject *kobj,
>>> +		struct attribute *attr, const char *buf, size_t count)
>>> +{
>>> +	struct ocfs2_sb_attr *oa =
>>> +		container_of(attr, struct ocfs2_sb_attr, attr);
>>> +	struct ocfs2_super *osb = container_of(kobj, struct ocfs2_super, kobj);
>>> +	if (!oa->store)
>>> +		return -EIO;
>>> +
>>> +	return oa->store(osb, oa, buf, count);
>>> +}
>>> +
>>> +static ssize_t slot_num_show(struct ocfs2_super *osb,
>>> +			     struct ocfs2_sb_attr *attr,
>>> +	  		     char *buf)
>>> +{
>>> +	return sprintf(buf, "%d\n", osb->slot_num);
>>> +}
>>> +
>>> +static void sb_release(struct kobject *kobj)
>>> +{
>>> +	struct ocfs2_super *osb = container_of(kobj, struct ocfs2_super, kobj);
>>> +	complete(&osb->kobj_unregister);
>>> +}
>>> +
>>> +static const struct sysfs_ops ocfs2_sb_sysfs_ops = {
>>> +	.show = ocfs2_sb_attr_show,
>>> +	.store = ocfs2_sb_attr_store,
>>> +};
>>> +
>>> +static OCFS2_SB_ATTR_RO(slot_num);
>>> +static struct attribute *ocfs2_sb_attrs[] = {
>>> +	&sb_attr_slot_num.attr,
>>> +	NULL
>>> +};
>>> +
>>> +static struct kobj_type ocfs2_sb_ktype = {
>>> +	.sysfs_ops 	= &ocfs2_sb_sysfs_ops,
>>> +	.default_attrs 	= ocfs2_sb_attrs,
>>> +	.release	= sb_release,
>>> +};
>>> +
>>> +
>>> +int ocfs2_sysfs_sb_init(struct super_block *sb)
>>> +{
>>> +	int err;
>>> +	struct ocfs2_super *osb = OCFS2_SB(sb);
>>> +	init_completion(&osb->kobj_unregister);
>>> +	osb->kobj.kset = ocfs2_kset;
>>> +	err = kobject_init_and_add(&osb->kobj, &ocfs2_sb_ktype, NULL, "%s", sb->s_id);
>>> +	return err;
>>> +
>>> +}
>>> +
>>> +void ocfs2_sysfs_sb_exit(struct super_block *sb)
>>> +{
>>> +	struct ocfs2_super *osb = OCFS2_SB(sb);
>>> +	kobject_del(&osb->kobj);
>>> +	kobject_put(&osb->kobj);
>>> +	wait_for_completion(&osb->kobj_unregister);
>>> +}
>>> +
>>> +
>>> diff --git a/fs/ocfs2/sysfs.h b/fs/ocfs2/sysfs.h
>>> new file mode 100644
>>> index 0000000..d929ac1
>>> --- /dev/null
>>> +++ b/fs/ocfs2/sysfs.h
>> Gang: please add header file comments like other header files.
>>
> 
> Agree.
> 
>>> @@ -0,0 +1,9 @@
>>> +
>>> +
>>> +#ifndef _SYS_H
>>> +#define _SYS_H
>>> +
>>> +int ocfs2_sysfs_sb_init(struct super_block *sb);
>>> +void ocfs2_sysfs_sb_exit(struct super_block *sb);
>>> +
>>> +#endif
>>> --
>>> 2.6.6
>>>
>>>
>>> _______________________________________________
>>> Ocfs2-devel mailing list
>>> Ocfs2-devel at oss.oracle.com 
>>> https://oss.oracle.com/mailman/listinfo/ocfs2-devel 
> 
> -- 
> Goldwyn



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